/*

  * Licensed to the Apache Software Foundation (ASF) under one or more

  * contributor license agreements.  See the NOTICE file distributed with

  * this work for additional information regarding copyright ownership.

  * The ASF licenses this file to You under the Apache License, Version 2.0

  * (the "License"); you may not use this file except in compliance with

  * the License.  You may obtain a copy of the License at

  *

  *  http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.apache.any23.validator;

 import org.w3c.dom.Element;

 import java.io.OutputStream;

 import java.io.PrintStream;

 import java.lang.annotation.Documented;

 import java.lang.annotation.ElementType;

 import java.lang.annotation.Retention;

 import java.lang.annotation.RetentionPolicy;

 import java.lang.annotation.Target;

 import java.lang.reflect.Array;

 import java.lang.reflect.Method;

 import java.lang.reflect.Modifier;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.List;

 /**

  * Default implementation of {@link ValidationReportSerializer}

  * for <i>XML</i>.

  *

  * @author Michele Mostarda (mostarda@fbk.eu)

  */

 public class XMLValidationReportSerializer implements ValidationReportSerializer {

     public void serialize(ValidationReport vr, OutputStream os) throws SerializationException {

         final PrintStream ps = new PrintStream(os);

         try {

             serializeObject(vr, ps);

         } finally {

             ps.flush();

         }

     }

     private void serializeObject(Object o, PrintStream ps) throws SerializationException {

         if(o == null) {

             return;

         }

         final Class oClass = o.getClass();

         final String oClassName = getClassName(oClass);

         ps.printf("<%s>\n", oClassName);

         List<Method> getters = filterGetters(o.getClass());

         if(getters.isEmpty()) {

             ps.print( o.toString() );

             return;

         }

         for (Method getter : getters) {

             serializeGetterValue(o, getter, ps);

         }

         ps.printf("</%s>\n", oClassName);

     }

     private String getClassName(Class oClass) {

         final NodeName nodeName = (NodeName) oClass.getAnnotation(NodeName.class);

         if(nodeName != null) {

             return nodeName.value();

         }

         final String simpleName = oClass.getSimpleName();

         return Character.toLowerCase(simpleName.charAt(0)) + simpleName.substring(1);

     }

     private List<Method> filterGetters(Class c) {

         Method[] methods = c.getDeclaredMethods();

         List<Method> filtered = new ArrayList<Method>();

         for(Method method : methods) {

             if(Modifier.isStatic(method.getModifiers())) {

                 continue;

             }

             final String methodName = method.getName();

             if(

                     method.getParameterTypes().length == 0

                         &&

                     (

                             (methodName.length() > 3 && methodName.indexOf("get") == 0)

                                     ||

                             (methodName.length() > 2 && methodName.indexOf("is")  == 0)

                     )

             ) {

                 filtered.add(method);

             }

         }

         return filtered;

     }

     public void serializeGetterValue(Object o, Method m, PrintStream ps) throws SerializationException {

         final Object value;

         final String methodName = m.getName();

         try {

             value = m.invoke(o);

         } catch (Exception e) {

             throw new SerializationException( String.format("Error while reading method '%s'", methodName), e );

         }

         final String property = getPropertyFromMethodName(methodName);

         if( isManaged(value) ) {

             ps.printf("<%s>\n", property);

             printObject(value, ps);

             ps.printf("</%s>\n", property);

         } else {

             List<Method> getters = filterGetters(value.getClass());

             for (Method getter : getters) {

                 serializeGetterValue(value, getter, ps);

             }

         }

     }

     private String getPropertyFromMethodName(String methodName) {

         int i = methodName.indexOf("is");

         if(i == 0) {

             return Character.toLowerCase( methodName.charAt(2) ) + methodName.substring(3);

         }

         return Character.toLowerCase( methodName.charAt(3) ) + methodName.substring(4);

     }

     private void printObject(Object o, PrintStream ps) throws SerializationException {

         if(o == null) {

             return;

         }

         if(o instanceof Element) {

             ps.print( o.toString() );

             return;

         }

         if(o instanceof Array) {

             Object[] array = (Object[]) o;

             if(array.length == 0) {

                 return;

             }

             for(Object a : array) {

                 serializeObject(a, ps);

             }

             return;

         }

         if(o instanceof Collection) {

             Collection collection = (Collection) o;

             if(collection.isEmpty()) {

                 return;

             }

             for(Object e : collection) {

                 serializeObject(e, ps);

             }

             return;

         }

         ps.print( o.toString() );

     }

     private boolean isManaged(Object o) {

         return

                 o == null

                         ||

                 o instanceof String

                         ||

                 o.getClass().isPrimitive()

                         ||

                 (o instanceof Collection)

                         ||

                 o instanceof Element;

     }

     /**

      * Allows to specify a custom node name.

      */

     @Documented

     @Retention(RetentionPolicy.RUNTIME)

     @Target(ElementType.TYPE)

     public @interface NodeName {

         String value();

     }

 }